This invention relates to a high-frequency electronic cooking device and more particularly to a microwave oven wherein the arrangement of a control panel and electric parts or elements connected with the control panel is substantially improved.
A conventional microwave oven generally comprises a box-shaped cabinet, a heating chamber provided in the box-shaped cabinet, an oven door provided on the front side of the heating chamber, and a control panel including a number of control switches and the like, provided on one lateral side of the heating chamber. Such a microwave oven has the drawback that it occupies a relatively wide horizontal space in a kitchen or the like in which effective utilization of a horizontal space is desired rather than that of a vertical space.
To eliminate this drawback of the conventional microwave oven, there has been proposed a microwave oven wherein the control panel is provided below the oven door. This type of microwave oven has a heating chamber provided in the box-shaped cabinet, an oven door pivotably provided on the front side of the heating chamber, a turntable for supporting foodstuff provided in the heating chamber, the turntable being rotated by an electric motor disposed below the heating chamber, and a control panel, as described above, now arranged below the oven door. The control panel extends vertically, and electric components including a printed circuit board connected with the switches and the like on the control panel are located at a portion of the cabinet below the heating chamber and on the rear side of the control panel.
With the construction of the newly-developed microwave oven, the lateral space occupied by the oven can be reduced in comparison with the aforementioned laterally elongated construction, without affecting its performance.
However, the electric components are inevitably provided within the cabinet of the microwave oven below the electric motor driving the turntable. Since most of the foodstuff placed on the turntable to be cooked contains a liquid substance, this substance tends to be spilled out of the turntable onto the bottom plate of the heat chamber, and then through a penetrating hole of a rotating shaft for the turntable to the electric motor while the foodstuff is heated in the heating chamber. Accordingly, the above-described arrangement having the printed circuit board and the like below the electric motor is not desirous because of the tendency of harm to the electrical insulation of the circuit board and the like caused by the liquid substance spilled out of the turntable. Furthermore, the temperature of the cabinet portion on the underside of the heating chamber ordinarily rises up to 70.degree. C. or more due to heat transmitted from the heating chamber. Exposure to such a temperature tends to deteriorate the circuit board and other electric parts or elements.